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00001 /***************************************************************************/ 00002 /* */ 00003 /* ftimage.h */ 00004 /* */ 00005 /* FreeType glyph image formats and default raster interface */ 00006 /* (specification). */ 00007 /* */ 00008 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, */ 00009 /* 2010 by */ 00010 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 00011 /* */ 00012 /* This file is part of the FreeType project, and may only be used, */ 00013 /* modified, and distributed under the terms of the FreeType project */ 00014 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 00015 /* this file you indicate that you have read the license and */ 00016 /* understand and accept it fully. */ 00017 /* */ 00018 /***************************************************************************/ 00019 00020 /*************************************************************************/ 00021 /* */ 00022 /* Note: A `raster' is simply a scan-line converter, used to render */ 00023 /* FT_Outlines into FT_Bitmaps. */ 00024 /* */ 00025 /*************************************************************************/ 00026 00027 00028 #ifndef __FTIMAGE_H__ 00029 #define __FTIMAGE_H__ 00030 00031 00032 /* _STANDALONE_ is from ftgrays.c */ 00033 #ifndef _STANDALONE_ 00034 #include <ft2build.h> 00035 #endif 00036 00037 00038 FT_BEGIN_HEADER 00039 00040 00041 /*************************************************************************/ 00042 /* */ 00043 /* <Section> */ 00044 /* basic_types */ 00045 /* */ 00046 /*************************************************************************/ 00047 00048 00049 /*************************************************************************/ 00050 /* */ 00051 /* <Type> */ 00052 /* FT_Pos */ 00053 /* */ 00054 /* <Description> */ 00055 /* The type FT_Pos is used to store vectorial coordinates. Depending */ 00056 /* on the context, these can represent distances in integer font */ 00057 /* units, or 16.16, or 26.6 fixed float pixel coordinates. */ 00058 /* */ 00059 typedef signed long FT_Pos; 00060 00061 00062 /*************************************************************************/ 00063 /* */ 00064 /* <Struct> */ 00065 /* FT_Vector */ 00066 /* */ 00067 /* <Description> */ 00068 /* A simple structure used to store a 2D vector; coordinates are of */ 00069 /* the FT_Pos type. */ 00070 /* */ 00071 /* <Fields> */ 00072 /* x :: The horizontal coordinate. */ 00073 /* y :: The vertical coordinate. */ 00074 /* */ 00075 typedef struct FT_Vector_ 00076 { 00077 FT_Pos x; 00078 FT_Pos y; 00079 00080 } FT_Vector; 00081 00082 00083 /*************************************************************************/ 00084 /* */ 00085 /* <Struct> */ 00086 /* FT_BBox */ 00087 /* */ 00088 /* <Description> */ 00089 /* A structure used to hold an outline's bounding box, i.e., the */ 00090 /* coordinates of its extrema in the horizontal and vertical */ 00091 /* directions. */ 00092 /* */ 00093 /* <Fields> */ 00094 /* xMin :: The horizontal minimum (left-most). */ 00095 /* */ 00096 /* yMin :: The vertical minimum (bottom-most). */ 00097 /* */ 00098 /* xMax :: The horizontal maximum (right-most). */ 00099 /* */ 00100 /* yMax :: The vertical maximum (top-most). */ 00101 /* */ 00102 /* <Note> */ 00103 /* The bounding box is specified with the coordinates of the lower */ 00104 /* left and the upper right corner. In PostScript, those values are */ 00105 /* often called (llx,lly) and (urx,ury), respectively. */ 00106 /* */ 00107 /* If `yMin' is negative, this value gives the glyph's descender. */ 00108 /* Otherwise, the glyph doesn't descend below the baseline. */ 00109 /* Similarly, if `ymax' is positive, this value gives the glyph's */ 00110 /* ascender. */ 00111 /* */ 00112 /* `xMin' gives the horizontal distance from the glyph's origin to */ 00113 /* the left edge of the glyph's bounding box. If `xMin' is negative, */ 00114 /* the glyph extends to the left of the origin. */ 00115 /* */ 00116 typedef struct FT_BBox_ 00117 { 00118 FT_Pos xMin, yMin; 00119 FT_Pos xMax, yMax; 00120 00121 } FT_BBox; 00122 00123 00124 /*************************************************************************/ 00125 /* */ 00126 /* <Enum> */ 00127 /* FT_Pixel_Mode */ 00128 /* */ 00129 /* <Description> */ 00130 /* An enumeration type used to describe the format of pixels in a */ 00131 /* given bitmap. Note that additional formats may be added in the */ 00132 /* future. */ 00133 /* */ 00134 /* <Values> */ 00135 /* FT_PIXEL_MODE_NONE :: */ 00136 /* Value~0 is reserved. */ 00137 /* */ 00138 /* FT_PIXEL_MODE_MONO :: */ 00139 /* A monochrome bitmap, using 1~bit per pixel. Note that pixels */ 00140 /* are stored in most-significant order (MSB), which means that */ 00141 /* the left-most pixel in a byte has value 128. */ 00142 /* */ 00143 /* FT_PIXEL_MODE_GRAY :: */ 00144 /* An 8-bit bitmap, generally used to represent anti-aliased glyph */ 00145 /* images. Each pixel is stored in one byte. Note that the number */ 00146 /* of `gray' levels is stored in the `num_grays' field of the */ 00147 /* @FT_Bitmap structure (it generally is 256). */ 00148 /* */ 00149 /* FT_PIXEL_MODE_GRAY2 :: */ 00150 /* A 2-bit per pixel bitmap, used to represent embedded */ 00151 /* anti-aliased bitmaps in font files according to the OpenType */ 00152 /* specification. We haven't found a single font using this */ 00153 /* format, however. */ 00154 /* */ 00155 /* FT_PIXEL_MODE_GRAY4 :: */ 00156 /* A 4-bit per pixel bitmap, representing embedded anti-aliased */ 00157 /* bitmaps in font files according to the OpenType specification. */ 00158 /* We haven't found a single font using this format, however. */ 00159 /* */ 00160 /* FT_PIXEL_MODE_LCD :: */ 00161 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */ 00162 /* used for display on LCD displays; the bitmap is three times */ 00163 /* wider than the original glyph image. See also */ 00164 /* @FT_RENDER_MODE_LCD. */ 00165 /* */ 00166 /* FT_PIXEL_MODE_LCD_V :: */ 00167 /* An 8-bit bitmap, representing RGB or BGR decimated glyph images */ 00168 /* used for display on rotated LCD displays; the bitmap is three */ 00169 /* times taller than the original glyph image. See also */ 00170 /* @FT_RENDER_MODE_LCD_V. */ 00171 /* */ 00172 typedef enum FT_Pixel_Mode_ 00173 { 00174 FT_PIXEL_MODE_NONE = 0, 00175 FT_PIXEL_MODE_MONO, 00176 FT_PIXEL_MODE_GRAY, 00177 FT_PIXEL_MODE_GRAY2, 00178 FT_PIXEL_MODE_GRAY4, 00179 FT_PIXEL_MODE_LCD, 00180 FT_PIXEL_MODE_LCD_V, 00181 00182 FT_PIXEL_MODE_MAX /* do not remove */ 00183 00184 } FT_Pixel_Mode; 00185 00186 00187 /*************************************************************************/ 00188 /* */ 00189 /* <Enum> */ 00190 /* ft_pixel_mode_xxx */ 00191 /* */ 00192 /* <Description> */ 00193 /* A list of deprecated constants. Use the corresponding */ 00194 /* @FT_Pixel_Mode values instead. */ 00195 /* */ 00196 /* <Values> */ 00197 /* ft_pixel_mode_none :: See @FT_PIXEL_MODE_NONE. */ 00198 /* ft_pixel_mode_mono :: See @FT_PIXEL_MODE_MONO. */ 00199 /* ft_pixel_mode_grays :: See @FT_PIXEL_MODE_GRAY. */ 00200 /* ft_pixel_mode_pal2 :: See @FT_PIXEL_MODE_GRAY2. */ 00201 /* ft_pixel_mode_pal4 :: See @FT_PIXEL_MODE_GRAY4. */ 00202 /* */ 00203 #define ft_pixel_mode_none FT_PIXEL_MODE_NONE 00204 #define ft_pixel_mode_mono FT_PIXEL_MODE_MONO 00205 #define ft_pixel_mode_grays FT_PIXEL_MODE_GRAY 00206 #define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2 00207 #define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4 00208 00209 /* */ 00210 00211 #if 0 00212 00213 /*************************************************************************/ 00214 /* */ 00215 /* <Enum> */ 00216 /* FT_Palette_Mode */ 00217 /* */ 00218 /* <Description> */ 00219 /* THIS TYPE IS DEPRECATED. DO NOT USE IT! */ 00220 /* */ 00221 /* An enumeration type to describe the format of a bitmap palette, */ 00222 /* used with ft_pixel_mode_pal4 and ft_pixel_mode_pal8. */ 00223 /* */ 00224 /* <Values> */ 00225 /* ft_palette_mode_rgb :: The palette is an array of 3-byte RGB */ 00226 /* records. */ 00227 /* */ 00228 /* ft_palette_mode_rgba :: The palette is an array of 4-byte RGBA */ 00229 /* records. */ 00230 /* */ 00231 /* <Note> */ 00232 /* As ft_pixel_mode_pal2, pal4 and pal8 are currently unused by */ 00233 /* FreeType, these types are not handled by the library itself. */ 00234 /* */ 00235 typedef enum FT_Palette_Mode_ 00236 { 00237 ft_palette_mode_rgb = 0, 00238 ft_palette_mode_rgba, 00239 00240 ft_palette_mode_max /* do not remove */ 00241 00242 } FT_Palette_Mode; 00243 00244 /* */ 00245 00246 #endif 00247 00248 00249 /*************************************************************************/ 00250 /* */ 00251 /* <Struct> */ 00252 /* FT_Bitmap */ 00253 /* */ 00254 /* <Description> */ 00255 /* A structure used to describe a bitmap or pixmap to the raster. */ 00256 /* Note that we now manage pixmaps of various depths through the */ 00257 /* `pixel_mode' field. */ 00258 /* */ 00259 /* <Fields> */ 00260 /* rows :: The number of bitmap rows. */ 00261 /* */ 00262 /* width :: The number of pixels in bitmap row. */ 00263 /* */ 00264 /* pitch :: The pitch's absolute value is the number of bytes */ 00265 /* taken by one bitmap row, including padding. */ 00266 /* However, the pitch is positive when the bitmap has */ 00267 /* a `down' flow, and negative when it has an `up' */ 00268 /* flow. In all cases, the pitch is an offset to add */ 00269 /* to a bitmap pointer in order to go down one row. */ 00270 /* */ 00271 /* Note that `padding' means the alignment of a */ 00272 /* bitmap to a byte border, and FreeType functions */ 00273 /* normally align to the smallest possible integer */ 00274 /* value. */ 00275 /* */ 00276 /* For the B/W rasterizer, `pitch' is always an even */ 00277 /* number. */ 00278 /* */ 00279 /* To change the pitch of a bitmap (say, to make it a */ 00280 /* multiple of 4), use @FT_Bitmap_Convert. */ 00281 /* Alternatively, you might use callback functions to */ 00282 /* directly render to the application's surface; see */ 00283 /* the file `example2.cpp' in the tutorial for a */ 00284 /* demonstration. */ 00285 /* */ 00286 /* buffer :: A typeless pointer to the bitmap buffer. This */ 00287 /* value should be aligned on 32-bit boundaries in */ 00288 /* most cases. */ 00289 /* */ 00290 /* num_grays :: This field is only used with */ 00291 /* @FT_PIXEL_MODE_GRAY; it gives the number of gray */ 00292 /* levels used in the bitmap. */ 00293 /* */ 00294 /* pixel_mode :: The pixel mode, i.e., how pixel bits are stored. */ 00295 /* See @FT_Pixel_Mode for possible values. */ 00296 /* */ 00297 /* palette_mode :: This field is intended for paletted pixel modes; */ 00298 /* it indicates how the palette is stored. Not */ 00299 /* used currently. */ 00300 /* */ 00301 /* palette :: A typeless pointer to the bitmap palette; this */ 00302 /* field is intended for paletted pixel modes. Not */ 00303 /* used currently. */ 00304 /* */ 00305 /* <Note> */ 00306 /* For now, the only pixel modes supported by FreeType are mono and */ 00307 /* grays. However, drivers might be added in the future to support */ 00308 /* more `colorful' options. */ 00309 /* */ 00310 typedef struct FT_Bitmap_ 00311 { 00312 int rows; 00313 int width; 00314 int pitch; 00315 unsigned char* buffer; 00316 short num_grays; 00317 char pixel_mode; 00318 char palette_mode; 00319 void* palette; 00320 00321 } FT_Bitmap; 00322 00323 00324 /*************************************************************************/ 00325 /* */ 00326 /* <Section> */ 00327 /* outline_processing */ 00328 /* */ 00329 /*************************************************************************/ 00330 00331 00332 /*************************************************************************/ 00333 /* */ 00334 /* <Struct> */ 00335 /* FT_Outline */ 00336 /* */ 00337 /* <Description> */ 00338 /* This structure is used to describe an outline to the scan-line */ 00339 /* converter. */ 00340 /* */ 00341 /* <Fields> */ 00342 /* n_contours :: The number of contours in the outline. */ 00343 /* */ 00344 /* n_points :: The number of points in the outline. */ 00345 /* */ 00346 /* points :: A pointer to an array of `n_points' @FT_Vector */ 00347 /* elements, giving the outline's point coordinates. */ 00348 /* */ 00349 /* tags :: A pointer to an array of `n_points' chars, giving */ 00350 /* each outline point's type. */ 00351 /* */ 00352 /* If bit~0 is unset, the point is `off' the curve, */ 00353 /* i.e., a Bézier control point, while it is `on' if */ 00354 /* set. */ 00355 /* */ 00356 /* Bit~1 is meaningful for `off' points only. If set, */ 00357 /* it indicates a third-order Bézier arc control point; */ 00358 /* and a second-order control point if unset. */ 00359 /* */ 00360 /* If bit~2 is set, bits 5-7 contain the drop-out mode */ 00361 /* (as defined in the OpenType specification; the value */ 00362 /* is the same as the argument to the SCANMODE */ 00363 /* instruction). */ 00364 /* */ 00365 /* Bits 3 and~4 are reserved for internal purposes. */ 00366 /* */ 00367 /* contours :: An array of `n_contours' shorts, giving the end */ 00368 /* point of each contour within the outline. For */ 00369 /* example, the first contour is defined by the points */ 00370 /* `0' to `contours[0]', the second one is defined by */ 00371 /* the points `contours[0]+1' to `contours[1]', etc. */ 00372 /* */ 00373 /* flags :: A set of bit flags used to characterize the outline */ 00374 /* and give hints to the scan-converter and hinter on */ 00375 /* how to convert/grid-fit it. See @FT_OUTLINE_FLAGS. */ 00376 /* */ 00377 /* <Note> */ 00378 /* The B/W rasterizer only checks bit~2 in the `tags' array for the */ 00379 /* first point of each contour. The drop-out mode as given with */ 00380 /* @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and */ 00381 /* @FT_OUTLINE_INCLUDE_STUBS in `flags' is then overridden. */ 00382 /* */ 00383 typedef struct FT_Outline_ 00384 { 00385 short n_contours; /* number of contours in glyph */ 00386 short n_points; /* number of points in the glyph */ 00387 00388 FT_Vector* points; /* the outline's points */ 00389 char* tags; /* the points flags */ 00390 short* contours; /* the contour end points */ 00391 00392 int flags; /* outline masks */ 00393 00394 } FT_Outline; 00395 00396 /* Following limits must be consistent with */ 00397 /* FT_Outline.{n_contours,n_points} */ 00398 #define FT_OUTLINE_CONTOURS_MAX SHRT_MAX 00399 #define FT_OUTLINE_POINTS_MAX SHRT_MAX 00400 00401 00402 /*************************************************************************/ 00403 /* */ 00404 /* <Enum> */ 00405 /* FT_OUTLINE_FLAGS */ 00406 /* */ 00407 /* <Description> */ 00408 /* A list of bit-field constants use for the flags in an outline's */ 00409 /* `flags' field. */ 00410 /* */ 00411 /* <Values> */ 00412 /* FT_OUTLINE_NONE :: */ 00413 /* Value~0 is reserved. */ 00414 /* */ 00415 /* FT_OUTLINE_OWNER :: */ 00416 /* If set, this flag indicates that the outline's field arrays */ 00417 /* (i.e., `points', `flags', and `contours') are `owned' by the */ 00418 /* outline object, and should thus be freed when it is destroyed. */ 00419 /* */ 00420 /* FT_OUTLINE_EVEN_ODD_FILL :: */ 00421 /* By default, outlines are filled using the non-zero winding rule. */ 00422 /* If set to 1, the outline will be filled using the even-odd fill */ 00423 /* rule (only works with the smooth rasterizer). */ 00424 /* */ 00425 /* FT_OUTLINE_REVERSE_FILL :: */ 00426 /* By default, outside contours of an outline are oriented in */ 00427 /* clock-wise direction, as defined in the TrueType specification. */ 00428 /* This flag is set if the outline uses the opposite direction */ 00429 /* (typically for Type~1 fonts). This flag is ignored by the scan */ 00430 /* converter. */ 00431 /* */ 00432 /* FT_OUTLINE_IGNORE_DROPOUTS :: */ 00433 /* By default, the scan converter will try to detect drop-outs in */ 00434 /* an outline and correct the glyph bitmap to ensure consistent */ 00435 /* shape continuity. If set, this flag hints the scan-line */ 00436 /* converter to ignore such cases. See below for more information. */ 00437 /* */ 00438 /* FT_OUTLINE_SMART_DROPOUTS :: */ 00439 /* Select smart dropout control. If unset, use simple dropout */ 00440 /* control. Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See */ 00441 /* below for more information. */ 00442 /* */ 00443 /* FT_OUTLINE_INCLUDE_STUBS :: */ 00444 /* If set, turn pixels on for `stubs', otherwise exclude them. */ 00445 /* Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See below for */ 00446 /* more information. */ 00447 /* */ 00448 /* FT_OUTLINE_HIGH_PRECISION :: */ 00449 /* This flag indicates that the scan-line converter should try to */ 00450 /* convert this outline to bitmaps with the highest possible */ 00451 /* quality. It is typically set for small character sizes. Note */ 00452 /* that this is only a hint that might be completely ignored by a */ 00453 /* given scan-converter. */ 00454 /* */ 00455 /* FT_OUTLINE_SINGLE_PASS :: */ 00456 /* This flag is set to force a given scan-converter to only use a */ 00457 /* single pass over the outline to render a bitmap glyph image. */ 00458 /* Normally, it is set for very large character sizes. It is only */ 00459 /* a hint that might be completely ignored by a given */ 00460 /* scan-converter. */ 00461 /* */ 00462 /* <Note> */ 00463 /* The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, */ 00464 /* and @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth */ 00465 /* rasterizer. */ 00466 /* */ 00467 /* There exists a second mechanism to pass the drop-out mode to the */ 00468 /* B/W rasterizer; see the `tags' field in @FT_Outline. */ 00469 /* */ 00470 /* Please refer to the description of the `SCANTYPE' instruction in */ 00471 /* the OpenType specification (in file `ttinst1.doc') how simple */ 00472 /* drop-outs, smart drop-outs, and stubs are defined. */ 00473 /* */ 00474 #define FT_OUTLINE_NONE 0x0 00475 #define FT_OUTLINE_OWNER 0x1 00476 #define FT_OUTLINE_EVEN_ODD_FILL 0x2 00477 #define FT_OUTLINE_REVERSE_FILL 0x4 00478 #define FT_OUTLINE_IGNORE_DROPOUTS 0x8 00479 #define FT_OUTLINE_SMART_DROPOUTS 0x10 00480 #define FT_OUTLINE_INCLUDE_STUBS 0x20 00481 00482 #define FT_OUTLINE_HIGH_PRECISION 0x100 00483 #define FT_OUTLINE_SINGLE_PASS 0x200 00484 00485 00486 /************************************************************************* 00487 * 00488 * @enum: 00489 * ft_outline_flags 00490 * 00491 * @description: 00492 * These constants are deprecated. Please use the corresponding 00493 * @FT_OUTLINE_FLAGS values. 00494 * 00495 * @values: 00496 * ft_outline_none :: See @FT_OUTLINE_NONE. 00497 * ft_outline_owner :: See @FT_OUTLINE_OWNER. 00498 * ft_outline_even_odd_fill :: See @FT_OUTLINE_EVEN_ODD_FILL. 00499 * ft_outline_reverse_fill :: See @FT_OUTLINE_REVERSE_FILL. 00500 * ft_outline_ignore_dropouts :: See @FT_OUTLINE_IGNORE_DROPOUTS. 00501 * ft_outline_high_precision :: See @FT_OUTLINE_HIGH_PRECISION. 00502 * ft_outline_single_pass :: See @FT_OUTLINE_SINGLE_PASS. 00503 */ 00504 #define ft_outline_none FT_OUTLINE_NONE 00505 #define ft_outline_owner FT_OUTLINE_OWNER 00506 #define ft_outline_even_odd_fill FT_OUTLINE_EVEN_ODD_FILL 00507 #define ft_outline_reverse_fill FT_OUTLINE_REVERSE_FILL 00508 #define ft_outline_ignore_dropouts FT_OUTLINE_IGNORE_DROPOUTS 00509 #define ft_outline_high_precision FT_OUTLINE_HIGH_PRECISION 00510 #define ft_outline_single_pass FT_OUTLINE_SINGLE_PASS 00511 00512 /* */ 00513 00514 #define FT_CURVE_TAG( flag ) ( flag & 3 ) 00515 00516 #define FT_CURVE_TAG_ON 1 00517 #define FT_CURVE_TAG_CONIC 0 00518 #define FT_CURVE_TAG_CUBIC 2 00519 00520 #define FT_CURVE_TAG_HAS_SCANMODE 4 00521 00522 #define FT_CURVE_TAG_TOUCH_X 8 /* reserved for the TrueType hinter */ 00523 #define FT_CURVE_TAG_TOUCH_Y 16 /* reserved for the TrueType hinter */ 00524 00525 #define FT_CURVE_TAG_TOUCH_BOTH ( FT_CURVE_TAG_TOUCH_X | \ 00526 FT_CURVE_TAG_TOUCH_Y ) 00527 00528 #define FT_Curve_Tag_On FT_CURVE_TAG_ON 00529 #define FT_Curve_Tag_Conic FT_CURVE_TAG_CONIC 00530 #define FT_Curve_Tag_Cubic FT_CURVE_TAG_CUBIC 00531 #define FT_Curve_Tag_Touch_X FT_CURVE_TAG_TOUCH_X 00532 #define FT_Curve_Tag_Touch_Y FT_CURVE_TAG_TOUCH_Y 00533 00534 00535 /*************************************************************************/ 00536 /* */ 00537 /* <FuncType> */ 00538 /* FT_Outline_MoveToFunc */ 00539 /* */ 00540 /* <Description> */ 00541 /* A function pointer type used to describe the signature of a `move */ 00542 /* to' function during outline walking/decomposition. */ 00543 /* */ 00544 /* A `move to' is emitted to start a new contour in an outline. */ 00545 /* */ 00546 /* <Input> */ 00547 /* to :: A pointer to the target point of the `move to'. */ 00548 /* */ 00549 /* user :: A typeless pointer which is passed from the caller of the */ 00550 /* decomposition function. */ 00551 /* */ 00552 /* <Return> */ 00553 /* Error code. 0~means success. */ 00554 /* */ 00555 typedef int 00556 (*FT_Outline_MoveToFunc)( const FT_Vector* to, 00557 void* user ); 00558 00559 #define FT_Outline_MoveTo_Func FT_Outline_MoveToFunc 00560 00561 00562 /*************************************************************************/ 00563 /* */ 00564 /* <FuncType> */ 00565 /* FT_Outline_LineToFunc */ 00566 /* */ 00567 /* <Description> */ 00568 /* A function pointer type used to describe the signature of a `line */ 00569 /* to' function during outline walking/decomposition. */ 00570 /* */ 00571 /* A `line to' is emitted to indicate a segment in the outline. */ 00572 /* */ 00573 /* <Input> */ 00574 /* to :: A pointer to the target point of the `line to'. */ 00575 /* */ 00576 /* user :: A typeless pointer which is passed from the caller of the */ 00577 /* decomposition function. */ 00578 /* */ 00579 /* <Return> */ 00580 /* Error code. 0~means success. */ 00581 /* */ 00582 typedef int 00583 (*FT_Outline_LineToFunc)( const FT_Vector* to, 00584 void* user ); 00585 00586 #define FT_Outline_LineTo_Func FT_Outline_LineToFunc 00587 00588 00589 /*************************************************************************/ 00590 /* */ 00591 /* <FuncType> */ 00592 /* FT_Outline_ConicToFunc */ 00593 /* */ 00594 /* <Description> */ 00595 /* A function pointer type used to describe the signature of a `conic */ 00596 /* to' function during outline walking or decomposition. */ 00597 /* */ 00598 /* A `conic to' is emitted to indicate a second-order Bézier arc in */ 00599 /* the outline. */ 00600 /* */ 00601 /* <Input> */ 00602 /* control :: An intermediate control point between the last position */ 00603 /* and the new target in `to'. */ 00604 /* */ 00605 /* to :: A pointer to the target end point of the conic arc. */ 00606 /* */ 00607 /* user :: A typeless pointer which is passed from the caller of */ 00608 /* the decomposition function. */ 00609 /* */ 00610 /* <Return> */ 00611 /* Error code. 0~means success. */ 00612 /* */ 00613 typedef int 00614 (*FT_Outline_ConicToFunc)( const FT_Vector* control, 00615 const FT_Vector* to, 00616 void* user ); 00617 00618 #define FT_Outline_ConicTo_Func FT_Outline_ConicToFunc 00619 00620 00621 /*************************************************************************/ 00622 /* */ 00623 /* <FuncType> */ 00624 /* FT_Outline_CubicToFunc */ 00625 /* */ 00626 /* <Description> */ 00627 /* A function pointer type used to describe the signature of a `cubic */ 00628 /* to' function during outline walking or decomposition. */ 00629 /* */ 00630 /* A `cubic to' is emitted to indicate a third-order Bézier arc. */ 00631 /* */ 00632 /* <Input> */ 00633 /* control1 :: A pointer to the first Bézier control point. */ 00634 /* */ 00635 /* control2 :: A pointer to the second Bézier control point. */ 00636 /* */ 00637 /* to :: A pointer to the target end point. */ 00638 /* */ 00639 /* user :: A typeless pointer which is passed from the caller of */ 00640 /* the decomposition function. */ 00641 /* */ 00642 /* <Return> */ 00643 /* Error code. 0~means success. */ 00644 /* */ 00645 typedef int 00646 (*FT_Outline_CubicToFunc)( const FT_Vector* control1, 00647 const FT_Vector* control2, 00648 const FT_Vector* to, 00649 void* user ); 00650 00651 #define FT_Outline_CubicTo_Func FT_Outline_CubicToFunc 00652 00653 00654 /*************************************************************************/ 00655 /* */ 00656 /* <Struct> */ 00657 /* FT_Outline_Funcs */ 00658 /* */ 00659 /* <Description> */ 00660 /* A structure to hold various function pointers used during outline */ 00661 /* decomposition in order to emit segments, conic, and cubic Béziers. */ 00662 /* */ 00663 /* <Fields> */ 00664 /* move_to :: The `move to' emitter. */ 00665 /* */ 00666 /* line_to :: The segment emitter. */ 00667 /* */ 00668 /* conic_to :: The second-order Bézier arc emitter. */ 00669 /* */ 00670 /* cubic_to :: The third-order Bézier arc emitter. */ 00671 /* */ 00672 /* shift :: The shift that is applied to coordinates before they */ 00673 /* are sent to the emitter. */ 00674 /* */ 00675 /* delta :: The delta that is applied to coordinates before they */ 00676 /* are sent to the emitter, but after the shift. */ 00677 /* */ 00678 /* <Note> */ 00679 /* The point coordinates sent to the emitters are the transformed */ 00680 /* version of the original coordinates (this is important for high */ 00681 /* accuracy during scan-conversion). The transformation is simple: */ 00682 /* */ 00683 /* { */ 00684 /* x' = (x << shift) - delta */ 00685 /* y' = (x << shift) - delta */ 00686 /* } */ 00687 /* */ 00688 /* Set the values of `shift' and `delta' to~0 to get the original */ 00689 /* point coordinates. */ 00690 /* */ 00691 typedef struct FT_Outline_Funcs_ 00692 { 00693 FT_Outline_MoveToFunc move_to; 00694 FT_Outline_LineToFunc line_to; 00695 FT_Outline_ConicToFunc conic_to; 00696 FT_Outline_CubicToFunc cubic_to; 00697 00698 int shift; 00699 FT_Pos delta; 00700 00701 } FT_Outline_Funcs; 00702 00703 00704 /*************************************************************************/ 00705 /* */ 00706 /* <Section> */ 00707 /* basic_types */ 00708 /* */ 00709 /*************************************************************************/ 00710 00711 00712 /*************************************************************************/ 00713 /* */ 00714 /* <Macro> */ 00715 /* FT_IMAGE_TAG */ 00716 /* */ 00717 /* <Description> */ 00718 /* This macro converts four-letter tags to an unsigned long type. */ 00719 /* */ 00720 /* <Note> */ 00721 /* Since many 16-bit compilers don't like 32-bit enumerations, you */ 00722 /* should redefine this macro in case of problems to something like */ 00723 /* this: */ 00724 /* */ 00725 /* { */ 00726 /* #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) value */ 00727 /* } */ 00728 /* */ 00729 /* to get a simple enumeration without assigning special numbers. */ 00730 /* */ 00731 #ifndef FT_IMAGE_TAG 00732 #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) \ 00733 value = ( ( (unsigned long)_x1 << 24 ) | \ 00734 ( (unsigned long)_x2 << 16 ) | \ 00735 ( (unsigned long)_x3 << 8 ) | \ 00736 (unsigned long)_x4 ) 00737 #endif /* FT_IMAGE_TAG */ 00738 00739 00740 /*************************************************************************/ 00741 /* */ 00742 /* <Enum> */ 00743 /* FT_Glyph_Format */ 00744 /* */ 00745 /* <Description> */ 00746 /* An enumeration type used to describe the format of a given glyph */ 00747 /* image. Note that this version of FreeType only supports two image */ 00748 /* formats, even though future font drivers will be able to register */ 00749 /* their own format. */ 00750 /* */ 00751 /* <Values> */ 00752 /* FT_GLYPH_FORMAT_NONE :: */ 00753 /* The value~0 is reserved. */ 00754 /* */ 00755 /* FT_GLYPH_FORMAT_COMPOSITE :: */ 00756 /* The glyph image is a composite of several other images. This */ 00757 /* format is _only_ used with @FT_LOAD_NO_RECURSE, and is used to */ 00758 /* report compound glyphs (like accented characters). */ 00759 /* */ 00760 /* FT_GLYPH_FORMAT_BITMAP :: */ 00761 /* The glyph image is a bitmap, and can be described as an */ 00762 /* @FT_Bitmap. You generally need to access the `bitmap' field of */ 00763 /* the @FT_GlyphSlotRec structure to read it. */ 00764 /* */ 00765 /* FT_GLYPH_FORMAT_OUTLINE :: */ 00766 /* The glyph image is a vectorial outline made of line segments */ 00767 /* and Bézier arcs; it can be described as an @FT_Outline; you */ 00768 /* generally want to access the `outline' field of the */ 00769 /* @FT_GlyphSlotRec structure to read it. */ 00770 /* */ 00771 /* FT_GLYPH_FORMAT_PLOTTER :: */ 00772 /* The glyph image is a vectorial path with no inside and outside */ 00773 /* contours. Some Type~1 fonts, like those in the Hershey family, */ 00774 /* contain glyphs in this format. These are described as */ 00775 /* @FT_Outline, but FreeType isn't currently capable of rendering */ 00776 /* them correctly. */ 00777 /* */ 00778 typedef enum FT_Glyph_Format_ 00779 { 00780 FT_IMAGE_TAG( FT_GLYPH_FORMAT_NONE, 0, 0, 0, 0 ), 00781 00782 FT_IMAGE_TAG( FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p' ), 00783 FT_IMAGE_TAG( FT_GLYPH_FORMAT_BITMAP, 'b', 'i', 't', 's' ), 00784 FT_IMAGE_TAG( FT_GLYPH_FORMAT_OUTLINE, 'o', 'u', 't', 'l' ), 00785 FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't' ) 00786 00787 } FT_Glyph_Format; 00788 00789 00790 /*************************************************************************/ 00791 /* */ 00792 /* <Enum> */ 00793 /* ft_glyph_format_xxx */ 00794 /* */ 00795 /* <Description> */ 00796 /* A list of deprecated constants. Use the corresponding */ 00797 /* @FT_Glyph_Format values instead. */ 00798 /* */ 00799 /* <Values> */ 00800 /* ft_glyph_format_none :: See @FT_GLYPH_FORMAT_NONE. */ 00801 /* ft_glyph_format_composite :: See @FT_GLYPH_FORMAT_COMPOSITE. */ 00802 /* ft_glyph_format_bitmap :: See @FT_GLYPH_FORMAT_BITMAP. */ 00803 /* ft_glyph_format_outline :: See @FT_GLYPH_FORMAT_OUTLINE. */ 00804 /* ft_glyph_format_plotter :: See @FT_GLYPH_FORMAT_PLOTTER. */ 00805 /* */ 00806 #define ft_glyph_format_none FT_GLYPH_FORMAT_NONE 00807 #define ft_glyph_format_composite FT_GLYPH_FORMAT_COMPOSITE 00808 #define ft_glyph_format_bitmap FT_GLYPH_FORMAT_BITMAP 00809 #define ft_glyph_format_outline FT_GLYPH_FORMAT_OUTLINE 00810 #define ft_glyph_format_plotter FT_GLYPH_FORMAT_PLOTTER 00811 00812 00813 /*************************************************************************/ 00814 /*************************************************************************/ 00815 /*************************************************************************/ 00816 /***** *****/ 00817 /***** R A S T E R D E F I N I T I O N S *****/ 00818 /***** *****/ 00819 /*************************************************************************/ 00820 /*************************************************************************/ 00821 /*************************************************************************/ 00822 00823 00824 /*************************************************************************/ 00825 /* */ 00826 /* A raster is a scan converter, in charge of rendering an outline into */ 00827 /* a a bitmap. This section contains the public API for rasters. */ 00828 /* */ 00829 /* Note that in FreeType 2, all rasters are now encapsulated within */ 00830 /* specific modules called `renderers'. See `freetype/ftrender.h' for */ 00831 /* more details on renderers. */ 00832 /* */ 00833 /*************************************************************************/ 00834 00835 00836 /*************************************************************************/ 00837 /* */ 00838 /* <Section> */ 00839 /* raster */ 00840 /* */ 00841 /* <Title> */ 00842 /* Scanline Converter */ 00843 /* */ 00844 /* <Abstract> */ 00845 /* How vectorial outlines are converted into bitmaps and pixmaps. */ 00846 /* */ 00847 /* <Description> */ 00848 /* This section contains technical definitions. */ 00849 /* */ 00850 /*************************************************************************/ 00851 00852 00853 /*************************************************************************/ 00854 /* */ 00855 /* <Type> */ 00856 /* FT_Raster */ 00857 /* */ 00858 /* <Description> */ 00859 /* A handle (pointer) to a raster object. Each object can be used */ 00860 /* independently to convert an outline into a bitmap or pixmap. */ 00861 /* */ 00862 typedef struct FT_RasterRec_* FT_Raster; 00863 00864 00865 /*************************************************************************/ 00866 /* */ 00867 /* <Struct> */ 00868 /* FT_Span */ 00869 /* */ 00870 /* <Description> */ 00871 /* A structure used to model a single span of gray (or black) pixels */ 00872 /* when rendering a monochrome or anti-aliased bitmap. */ 00873 /* */ 00874 /* <Fields> */ 00875 /* x :: The span's horizontal start position. */ 00876 /* */ 00877 /* len :: The span's length in pixels. */ 00878 /* */ 00879 /* coverage :: The span color/coverage, ranging from 0 (background) */ 00880 /* to 255 (foreground). Only used for anti-aliased */ 00881 /* rendering. */ 00882 /* */ 00883 /* <Note> */ 00884 /* This structure is used by the span drawing callback type named */ 00885 /* @FT_SpanFunc which takes the y~coordinate of the span as a */ 00886 /* a parameter. */ 00887 /* */ 00888 /* The coverage value is always between 0 and 255. If you want less */ 00889 /* gray values, the callback function has to reduce them. */ 00890 /* */ 00891 typedef struct FT_Span_ 00892 { 00893 short x; 00894 unsigned short len; 00895 unsigned char coverage; 00896 00897 } FT_Span; 00898 00899 00900 /*************************************************************************/ 00901 /* */ 00902 /* <FuncType> */ 00903 /* FT_SpanFunc */ 00904 /* */ 00905 /* <Description> */ 00906 /* A function used as a call-back by the anti-aliased renderer in */ 00907 /* order to let client applications draw themselves the gray pixel */ 00908 /* spans on each scan line. */ 00909 /* */ 00910 /* <Input> */ 00911 /* y :: The scanline's y~coordinate. */ 00912 /* */ 00913 /* count :: The number of spans to draw on this scanline. */ 00914 /* */ 00915 /* spans :: A table of `count' spans to draw on the scanline. */ 00916 /* */ 00917 /* user :: User-supplied data that is passed to the callback. */ 00918 /* */ 00919 /* <Note> */ 00920 /* This callback allows client applications to directly render the */ 00921 /* gray spans of the anti-aliased bitmap to any kind of surfaces. */ 00922 /* */ 00923 /* This can be used to write anti-aliased outlines directly to a */ 00924 /* given background bitmap, and even perform translucency. */ 00925 /* */ 00926 /* Note that the `count' field cannot be greater than a fixed value */ 00927 /* defined by the `FT_MAX_GRAY_SPANS' configuration macro in */ 00928 /* `ftoption.h'. By default, this value is set to~32, which means */ 00929 /* that if there are more than 32~spans on a given scanline, the */ 00930 /* callback is called several times with the same `y' parameter in */ 00931 /* order to draw all callbacks. */ 00932 /* */ 00933 /* Otherwise, the callback is only called once per scan-line, and */ 00934 /* only for those scanlines that do have `gray' pixels on them. */ 00935 /* */ 00936 typedef void 00937 (*FT_SpanFunc)( int y, 00938 int count, 00939 const FT_Span* spans, 00940 void* user ); 00941 00942 #define FT_Raster_Span_Func FT_SpanFunc 00943 00944 00945 /*************************************************************************/ 00946 /* */ 00947 /* <FuncType> */ 00948 /* FT_Raster_BitTest_Func */ 00949 /* */ 00950 /* <Description> */ 00951 /* THIS TYPE IS DEPRECATED. DO NOT USE IT. */ 00952 /* */ 00953 /* A function used as a call-back by the monochrome scan-converter */ 00954 /* to test whether a given target pixel is already set to the drawing */ 00955 /* `color'. These tests are crucial to implement drop-out control */ 00956 /* per-se the TrueType spec. */ 00957 /* */ 00958 /* <Input> */ 00959 /* y :: The pixel's y~coordinate. */ 00960 /* */ 00961 /* x :: The pixel's x~coordinate. */ 00962 /* */ 00963 /* user :: User-supplied data that is passed to the callback. */ 00964 /* */ 00965 /* <Return> */ 00966 /* 1~if the pixel is `set', 0~otherwise. */ 00967 /* */ 00968 typedef int 00969 (*FT_Raster_BitTest_Func)( int y, 00970 int x, 00971 void* user ); 00972 00973 00974 /*************************************************************************/ 00975 /* */ 00976 /* <FuncType> */ 00977 /* FT_Raster_BitSet_Func */ 00978 /* */ 00979 /* <Description> */ 00980 /* THIS TYPE IS DEPRECATED. DO NOT USE IT. */ 00981 /* */ 00982 /* A function used as a call-back by the monochrome scan-converter */ 00983 /* to set an individual target pixel. This is crucial to implement */ 00984 /* drop-out control according to the TrueType specification. */ 00985 /* */ 00986 /* <Input> */ 00987 /* y :: The pixel's y~coordinate. */ 00988 /* */ 00989 /* x :: The pixel's x~coordinate. */ 00990 /* */ 00991 /* user :: User-supplied data that is passed to the callback. */ 00992 /* */ 00993 /* <Return> */ 00994 /* 1~if the pixel is `set', 0~otherwise. */ 00995 /* */ 00996 typedef void 00997 (*FT_Raster_BitSet_Func)( int y, 00998 int x, 00999 void* user ); 01000 01001 01002 /*************************************************************************/ 01003 /* */ 01004 /* <Enum> */ 01005 /* FT_RASTER_FLAG_XXX */ 01006 /* */ 01007 /* <Description> */ 01008 /* A list of bit flag constants as used in the `flags' field of a */ 01009 /* @FT_Raster_Params structure. */ 01010 /* */ 01011 /* <Values> */ 01012 /* FT_RASTER_FLAG_DEFAULT :: This value is 0. */ 01013 /* */ 01014 /* FT_RASTER_FLAG_AA :: This flag is set to indicate that an */ 01015 /* anti-aliased glyph image should be */ 01016 /* generated. Otherwise, it will be */ 01017 /* monochrome (1-bit). */ 01018 /* */ 01019 /* FT_RASTER_FLAG_DIRECT :: This flag is set to indicate direct */ 01020 /* rendering. In this mode, client */ 01021 /* applications must provide their own span */ 01022 /* callback. This lets them directly */ 01023 /* draw or compose over an existing bitmap. */ 01024 /* If this bit is not set, the target */ 01025 /* pixmap's buffer _must_ be zeroed before */ 01026 /* rendering. */ 01027 /* */ 01028 /* Note that for now, direct rendering is */ 01029 /* only possible with anti-aliased glyphs. */ 01030 /* */ 01031 /* FT_RASTER_FLAG_CLIP :: This flag is only used in direct */ 01032 /* rendering mode. If set, the output will */ 01033 /* be clipped to a box specified in the */ 01034 /* `clip_box' field of the */ 01035 /* @FT_Raster_Params structure. */ 01036 /* */ 01037 /* Note that by default, the glyph bitmap */ 01038 /* is clipped to the target pixmap, except */ 01039 /* in direct rendering mode where all spans */ 01040 /* are generated if no clipping box is set. */ 01041 /* */ 01042 #define FT_RASTER_FLAG_DEFAULT 0x0 01043 #define FT_RASTER_FLAG_AA 0x1 01044 #define FT_RASTER_FLAG_DIRECT 0x2 01045 #define FT_RASTER_FLAG_CLIP 0x4 01046 01047 /* deprecated */ 01048 #define ft_raster_flag_default FT_RASTER_FLAG_DEFAULT 01049 #define ft_raster_flag_aa FT_RASTER_FLAG_AA 01050 #define ft_raster_flag_direct FT_RASTER_FLAG_DIRECT 01051 #define ft_raster_flag_clip FT_RASTER_FLAG_CLIP 01052 01053 01054 /*************************************************************************/ 01055 /* */ 01056 /* <Struct> */ 01057 /* FT_Raster_Params */ 01058 /* */ 01059 /* <Description> */ 01060 /* A structure to hold the arguments used by a raster's render */ 01061 /* function. */ 01062 /* */ 01063 /* <Fields> */ 01064 /* target :: The target bitmap. */ 01065 /* */ 01066 /* source :: A pointer to the source glyph image (e.g., an */ 01067 /* @FT_Outline). */ 01068 /* */ 01069 /* flags :: The rendering flags. */ 01070 /* */ 01071 /* gray_spans :: The gray span drawing callback. */ 01072 /* */ 01073 /* black_spans :: The black span drawing callback. UNIMPLEMENTED! */ 01074 /* */ 01075 /* bit_test :: The bit test callback. UNIMPLEMENTED! */ 01076 /* */ 01077 /* bit_set :: The bit set callback. UNIMPLEMENTED! */ 01078 /* */ 01079 /* user :: User-supplied data that is passed to each drawing */ 01080 /* callback. */ 01081 /* */ 01082 /* clip_box :: An optional clipping box. It is only used in */ 01083 /* direct rendering mode. Note that coordinates here */ 01084 /* should be expressed in _integer_ pixels (and not in */ 01085 /* 26.6 fixed-point units). */ 01086 /* */ 01087 /* <Note> */ 01088 /* An anti-aliased glyph bitmap is drawn if the @FT_RASTER_FLAG_AA */ 01089 /* bit flag is set in the `flags' field, otherwise a monochrome */ 01090 /* bitmap is generated. */ 01091 /* */ 01092 /* If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags', the */ 01093 /* raster will call the `gray_spans' callback to draw gray pixel */ 01094 /* spans, in the case of an aa glyph bitmap, it will call */ 01095 /* `black_spans', and `bit_test' and `bit_set' in the case of a */ 01096 /* monochrome bitmap. This allows direct composition over a */ 01097 /* pre-existing bitmap through user-provided callbacks to perform the */ 01098 /* span drawing/composition. */ 01099 /* */ 01100 /* Note that the `bit_test' and `bit_set' callbacks are required when */ 01101 /* rendering a monochrome bitmap, as they are crucial to implement */ 01102 /* correct drop-out control as defined in the TrueType specification. */ 01103 /* */ 01104 typedef struct FT_Raster_Params_ 01105 { 01106 const FT_Bitmap* target; 01107 const void* source; 01108 int flags; 01109 FT_SpanFunc gray_spans; 01110 FT_SpanFunc black_spans; /* doesn't work! */ 01111 FT_Raster_BitTest_Func bit_test; /* doesn't work! */ 01112 FT_Raster_BitSet_Func bit_set; /* doesn't work! */ 01113 void* user; 01114 FT_BBox clip_box; 01115 01116 } FT_Raster_Params; 01117 01118 01119 /*************************************************************************/ 01120 /* */ 01121 /* <FuncType> */ 01122 /* FT_Raster_NewFunc */ 01123 /* */ 01124 /* <Description> */ 01125 /* A function used to create a new raster object. */ 01126 /* */ 01127 /* <Input> */ 01128 /* memory :: A handle to the memory allocator. */ 01129 /* */ 01130 /* <Output> */ 01131 /* raster :: A handle to the new raster object. */ 01132 /* */ 01133 /* <Return> */ 01134 /* Error code. 0~means success. */ 01135 /* */ 01136 /* <Note> */ 01137 /* The `memory' parameter is a typeless pointer in order to avoid */ 01138 /* un-wanted dependencies on the rest of the FreeType code. In */ 01139 /* practice, it is an @FT_Memory object, i.e., a handle to the */ 01140 /* standard FreeType memory allocator. However, this field can be */ 01141 /* completely ignored by a given raster implementation. */ 01142 /* */ 01143 typedef int 01144 (*FT_Raster_NewFunc)( void* memory, 01145 FT_Raster* raster ); 01146 01147 #define FT_Raster_New_Func FT_Raster_NewFunc 01148 01149 01150 /*************************************************************************/ 01151 /* */ 01152 /* <FuncType> */ 01153 /* FT_Raster_DoneFunc */ 01154 /* */ 01155 /* <Description> */ 01156 /* A function used to destroy a given raster object. */ 01157 /* */ 01158 /* <Input> */ 01159 /* raster :: A handle to the raster object. */ 01160 /* */ 01161 typedef void 01162 (*FT_Raster_DoneFunc)( FT_Raster raster ); 01163 01164 #define FT_Raster_Done_Func FT_Raster_DoneFunc 01165 01166 01167 /*************************************************************************/ 01168 /* */ 01169 /* <FuncType> */ 01170 /* FT_Raster_ResetFunc */ 01171 /* */ 01172 /* <Description> */ 01173 /* FreeType provides an area of memory called the `render pool', */ 01174 /* available to all registered rasters. This pool can be freely used */ 01175 /* during a given scan-conversion but is shared by all rasters. Its */ 01176 /* content is thus transient. */ 01177 /* */ 01178 /* This function is called each time the render pool changes, or just */ 01179 /* after a new raster object is created. */ 01180 /* */ 01181 /* <Input> */ 01182 /* raster :: A handle to the new raster object. */ 01183 /* */ 01184 /* pool_base :: The address in memory of the render pool. */ 01185 /* */ 01186 /* pool_size :: The size in bytes of the render pool. */ 01187 /* */ 01188 /* <Note> */ 01189 /* Rasters can ignore the render pool and rely on dynamic memory */ 01190 /* allocation if they want to (a handle to the memory allocator is */ 01191 /* passed to the raster constructor). However, this is not */ 01192 /* recommended for efficiency purposes. */ 01193 /* */ 01194 typedef void 01195 (*FT_Raster_ResetFunc)( FT_Raster raster, 01196 unsigned char* pool_base, 01197 unsigned long pool_size ); 01198 01199 #define FT_Raster_Reset_Func FT_Raster_ResetFunc 01200 01201 01202 /*************************************************************************/ 01203 /* */ 01204 /* <FuncType> */ 01205 /* FT_Raster_SetModeFunc */ 01206 /* */ 01207 /* <Description> */ 01208 /* This function is a generic facility to change modes or attributes */ 01209 /* in a given raster. This can be used for debugging purposes, or */ 01210 /* simply to allow implementation-specific `features' in a given */ 01211 /* raster module. */ 01212 /* */ 01213 /* <Input> */ 01214 /* raster :: A handle to the new raster object. */ 01215 /* */ 01216 /* mode :: A 4-byte tag used to name the mode or property. */ 01217 /* */ 01218 /* args :: A pointer to the new mode/property to use. */ 01219 /* */ 01220 typedef int 01221 (*FT_Raster_SetModeFunc)( FT_Raster raster, 01222 unsigned long mode, 01223 void* args ); 01224 01225 #define FT_Raster_Set_Mode_Func FT_Raster_SetModeFunc 01226 01227 01228 /*************************************************************************/ 01229 /* */ 01230 /* <FuncType> */ 01231 /* FT_Raster_RenderFunc */ 01232 /* */ 01233 /* <Description> */ 01234 /* Invoke a given raster to scan-convert a given glyph image into a */ 01235 /* target bitmap. */ 01236 /* */ 01237 /* <Input> */ 01238 /* raster :: A handle to the raster object. */ 01239 /* */ 01240 /* params :: A pointer to an @FT_Raster_Params structure used to */ 01241 /* store the rendering parameters. */ 01242 /* */ 01243 /* <Return> */ 01244 /* Error code. 0~means success. */ 01245 /* */ 01246 /* <Note> */ 01247 /* The exact format of the source image depends on the raster's glyph */ 01248 /* format defined in its @FT_Raster_Funcs structure. It can be an */ 01249 /* @FT_Outline or anything else in order to support a large array of */ 01250 /* glyph formats. */ 01251 /* */ 01252 /* Note also that the render function can fail and return a */ 01253 /* `FT_Err_Unimplemented_Feature' error code if the raster used does */ 01254 /* not support direct composition. */ 01255 /* */ 01256 /* XXX: For now, the standard raster doesn't support direct */ 01257 /* composition but this should change for the final release (see */ 01258 /* the files `demos/src/ftgrays.c' and `demos/src/ftgrays2.c' */ 01259 /* for examples of distinct implementations which support direct */ 01260 /* composition). */ 01261 /* */ 01262 typedef int 01263 (*FT_Raster_RenderFunc)( FT_Raster raster, 01264 const FT_Raster_Params* params ); 01265 01266 #define FT_Raster_Render_Func FT_Raster_RenderFunc 01267 01268 01269 /*************************************************************************/ 01270 /* */ 01271 /* <Struct> */ 01272 /* FT_Raster_Funcs */ 01273 /* */ 01274 /* <Description> */ 01275 /* A structure used to describe a given raster class to the library. */ 01276 /* */ 01277 /* <Fields> */ 01278 /* glyph_format :: The supported glyph format for this raster. */ 01279 /* */ 01280 /* raster_new :: The raster constructor. */ 01281 /* */ 01282 /* raster_reset :: Used to reset the render pool within the raster. */ 01283 /* */ 01284 /* raster_render :: A function to render a glyph into a given bitmap. */ 01285 /* */ 01286 /* raster_done :: The raster destructor. */ 01287 /* */ 01288 typedef struct FT_Raster_Funcs_ 01289 { 01290 FT_Glyph_Format glyph_format; 01291 FT_Raster_NewFunc raster_new; 01292 FT_Raster_ResetFunc raster_reset; 01293 FT_Raster_SetModeFunc raster_set_mode; 01294 FT_Raster_RenderFunc raster_render; 01295 FT_Raster_DoneFunc raster_done; 01296 01297 } FT_Raster_Funcs; 01298 01299 01300 /* */ 01301 01302 01303 FT_END_HEADER 01304 01305 #endif /* __FTIMAGE_H__ */ 01306 01307 01308 /* END */ 01309 01310 01311 /* Local Variables: */ 01312 /* coding: utf-8 */ 01313 /* End: */
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